Nasal cannula

ABSTRACT

A unified nasal cannula comprises a hollow tubular body having an upper flat or plane surface and a pair of spaced and curved elongated tubular extensions, having exterior orifices for directing a gas flow which extensions project upwardly at an angle from the surface.

United States Hudson et a1.

[ 5] Feb. 22, 1972 [541 NASAL CANNULA [72] lnventors: Allan C. Hudson,3323 Sparr Boulevard, Glendale, Calif. 91208; John M. Kinnear, 20515 SanGabriel Valley Drive, Walnut, Calif. 91789; Harold R. Havstad, 6612Centralia, Lakewood, Calif. 90713 [22] Filed: Nov.21, 1969 [21]App1.No.: 878,628

[52] U.S.Cl ..128/206 [51] ..A6lm 15/08 [58] Field of Search ..128/205,140 N, 198, 199, 200,

[56] References Cited UNITED STATES PATENTS 2,663,297 12/1953 Tumberg..128/206 2,215,126 9/1940 McMillin ..128/148 2,693,800 11/1954 Caldwell1 28/206 2,763,263 9/1956 Ellman ...128/ 198 2,868,199 1/1959 Hudson...128/206 2,931,358 4/1960 Sheridan.... ...128/206 3,161,199 12/1964Sands ...128/348 3,400,714 9/1968 Sheridan ..128/206 PrimaryExaminer-Richard A. Gaudet Assistant ExaminerJ. B. MitchellAttorneyJerry R. Seiler ABSTRACT A unified nasal cannula comprises ahollow tubular body having an upper flat or plane surface and a pair ofspaced and curved elongated tubular extensions, having exterior orificesfor directing a gas flow which extensions project upwardly at an anglefrom the surface.

13 Claims, 4 Drawing Figures PATENTEnrmza I972 3; 643 660 f/ g 3 I'INVENTOR.

NASAL CANNULA BACKGROUND OF THE INVENTION One of the most efficientmethods of administering therapeutic oxygen to patients has beenaccomplished by the use of nasal cannulae. Early cannula models weresomewhat cumbersome due not only to their relatively large sizes, butalso in the manner by which they were affixed to the patient. Forexample, devices were attached to the users forehead or utilized strapmeans which extended around the cheeks to the back of the patients head.With the advent of plastic tubing, a number of improvements wererealized, both as to the more efficient oxygen administration, as wellas to the patients comfort, for example, as disclosed in US. Pat. Nos.2,735,432 and 2,868,199. These cannulae are designed so that gases flowdirectly into the patients nasal passages and pharynx. This object wasachieved by tilting a flattened portion of the cannula which liesagainst the patients face or cheeks, with respect to the plane of theelongated nasal extensions and by curving these extensions in a mannerso as to conform with the shape of the nasal passageways.

Notwithstanding such improvements, there remained some disadvantagesnotably in the area of patient discomfort. The above-noted cannulae, aswell as others, in view of their design, generally have been placed onthe user so as to be primarily positioned or seated in the nasolabialarea, i.e., the area between the patients upper lip and the nostrils.Even though such devices are made of soft, flexible plastic or rubber,in attempts to minimize skin irritation at the points of contact, somediscomfort is known to persist. For example, when a patient is requiredto have prolonged oxygen administration thereby necessitating constantwearing of the cannula, both during awakening as well as sleeping hours,continued contact of the cannula, especially at the philtrum and aroundthe unprotected upper lip and cheek areas causes inflammation andirritation. Not only does the wearer, inadvertently move the cannulawhile sleeping as the head moves from side to side, but when eatingand/or talking, further movement occurs. There is also associateddiscomfort and inconvenience, particularly in talking or eating wherethe device is firmly positioned against the upper lip area and acrossthe cheeks. As in the case in any instances of prolonged contact of thepatients skin with an object, not only does irritation result, butinflammation and ulcerous conditions may occur after a period of time.

A further disadvantage associated with prior cannulae is in the methodin which they are placed on the patient. Where a strap or elastic bandis required to be secured around the back of the patients head, the headmust be lifted. In cases where the patient suffers from a serious back,head or neck injury, movement of the head is quite undesirable and couldcause additional injury. It is to the reduction or elimination of theabove-noted disadvantages that the preset invention is directed.

SUMMARY OF THE INVENTION The nasal cannula described herein comprises abody portion having a hollow tunnel or tubular area extendingtherethrough and which body portion has an upper generally flat surface.A pair of spaced elongated tubular extensions extend from the flatsurface. The extensions have an outer orifice for directing a gas flowto the nasal passageways of the patient and a lower interior orificecommunicating with the tubular area of the body portion. The terminationof the tubular area extending through the body provides an opening ateach end, which openings may be connected to an oxygen supply tube. Thetubular extensions are preferably curved so that they intersect the flatsurface of the body portion at an angle. In use, the cannula when fittedto the patient is positioned so that the flat surface lies across thenostrils (anterior nares) and the approximate center thereof between thespaced tubular extensions rests upon the exterior nasal septum. In thismanner, contact of the cannula with the upper lip area is essentiallyavoided with patient discomfort and .skin irritation minimized. These,as well as other advantages will be described and become more evidentfrom the following detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 4 illustrates a preferred methodby which the cannula is secured to the patient utilizing the oxygensupply tubes.

DETAILED DESCRIPTION OF THE INVENTION Referring to FIGS. 1 and 2, theconstruction of the nasal cannula 10 includes a body portion 11, havinga hollow tunnel 17 through the entire length of the body portion II.Exterior openings 16 of the tunnel 17 are located at each end of thebody portion 11. The size or diameter of the tunnel I7 is notparticularly critical so long as it is essentially uniform throughoutand sufficient to allow for unrestricted passage of gas therethrough.However, the diameter of the tunnel opening 16 should be great enough toallow for insertion of oxygen supply tubes 24 and 25. These supply tubesare preferably of catheter size, for example, having an externaldiameter of about 0.125 inches. The upper surface 12 of the body portion11 is flattened so as to provide a smooth surface for contacting thepatients nostrils and exterior nasal septum, although it may be slightlyoutwardly curved. The surface l2 not only provides for patient comfort,but, in addition and of more importance, prevents the cannula fromturning or rotating thereby maintaining its proper position during use.Thus, with the flat surface engaging the anterior nares, the cannuladoes not tend to roll which would otherwise cause the tubular extensionsto be displaced from within the nostrils. The rear edge 20 of the uppersurface 12 is preferably rounded to provide a smooth surface should itcontact the nasolabial area between a patients upper lip and nostrils.This feature is also shown in FIG. 3. The underside of lower surface 18of the cannula body II as shown is shaped as the exterior diameter ofthe tunnel 17, but may have alternate form. However, in the interest ofbeing lightweight and flexible, by molding the cannula 10 to have ageneral shape as shown, material requirements are minimized andsimplified molding techniques may be utilized.

Integral with the cannula body I I and protruding or extending from theupper flat surface 12 are a pair of spaced tubular extensions 14. Theseextensions 14 are desirably curved, as shown, so that when placed withinthe nasal cavities (Note FIG. 3) they conform to the shape of thepassageway as well as providing a smooth surface which may contact thedelicate nasal membranes. It will be noted in FIG. 3 that the lowerinternal orifice 30 of each of the tubular extensions 14 open to thehollow tunnel 17 of the cannula body 11. Then, as oxygen is introducedinto the cannula 10 through the oxygen supply tubes 24 and 25, there isan unrestricted passageway for entry of the oxygen through the orifices30 of each of the tubular extensions 14 which oxygen then passes upwardthrough the tubular extensions 14 and out of the upper external orifices15. Thus, the oxygen is directly introduced into the patients nasalcavity and pharynx.

As best seen in FIGS. 1 and 3, the tubular extensions 14 intersect withthe upper flat surface 12 of the cannula body 1 l at an angle which ispreferably obtuse with the plane of the surface 12. The tubularextensions 14 are also preferably located at or near the forward edge of22 of the surface I2, which location combined with the angle ofintersection of the tubular extensions I4 with that surface providemaximum comfort to the patient and easy placement of the cannulaextensions 14 into the nasal passageways. Although the extensions 14 maybe curved to any desired extent, it has also been found that for mostpatients having normal nasal passageway contours where the plane of theexternal gas directing orifices 15 is essentially normal to the plane ofthe flat surface 12, proper gas flow direction and maximum patientcomfort will be achieved. However, the greater or lesser curvatures ofthese tubular extensions 14 may be utilized depending on individualpatient requirements. Yet, clue to the flexibility of these extensions14 small angle deviation is possible by inserting the cannula extensionsinto the patients nostrils with concomitant movement of the extensionsso as to conform to the patients nasal cavity.

Another preferred feature is in utilizing flared extensions 14. Theflaring is preferably uniform between the lower internal orifice 30 andupper exterior orifice 15, resulting in a reduced velocity gas flow fromthe external orifice 15 as compared to the velocity at which the gasenters the lower orifice 30. Thus, although the same volume of gas willbe delivered to the patient, the reduced gas velocity entering the nasalcavity avoids high-velocity impingement on the delicate nasal cavitymembrane which could cause oxygen burn, irritation and discomfort. Theamount of flaring between the external orifice 15 and the internalorifice 30 may be varied to any desired extent with diameter ratiosbetween about 221 and about 4:l respectively being preferred.

The size of the cannula is not particularly critical with the provisionthat the length and width of the upper flat surface 12 to be such thatit will rest comfortably when placed on the patient. Thus, for example,a length of the surface 12 being between about 1% and about 2 incheswill ensure that it will span the width of the nostrils. Further, thewidth of the flat surface 12, i.e., the distance between the edges 22and 20 should be sufficient to provide a comfortable contact area withthe nostrils and nasal septum, while at the same time, holding thecannula firmly in place when on the patient. However, it should also beunderstood that this distance should not be excessive which wouldotherwise cause edge 20 to engage the upper lip area excessively,resulting in discomfort or irritation. In addition, the tubularextensions 14 should be separated or spaced so that they are comfortableand can be easilyinserted into the nasal passages. It will beappreciated that such dimensional requirements will vary betweenindividual patients depending on age, size, facial features, etc. Thus,cannula model sizes may be varied accordingly.

FIG. 4 illustrates a preferred manner in which the cannula is worn by apatient. The cannula l rests across the patients nostril area (anteriornares) and the flexible oxygen supply tubes 24 and 25 are brought acrossthe patients face, over and behind the ears, down the jaw areas andbrought together under the chin. A hollow sliding member 28 ofsufficient size to encompass both tubes 24 and 25, may then be adjustedso that the cannula will remain firmly in place without the tubes beingunduly taunt. The cannula 10 may be easily removed by sliding the member28 downwardly so that the supply tubes 24 and 25 become loosened. Inthis manner the cannula can be easily placed on a patient and removedwithout moving the patients head. The oxygen supply tubes 24 and 25 maybe fitted into a larger oxygen supply tube which in turn is connected toan oxygen source as will be understood by those skilled in the art.

The above-described invention provides an oxygen administration devicewhich not only can be easily fitted to and removed from a patient, butwhich is of minimum discomfort and irritation to the patient. Thus,since the cannula essentially contacts only the exterior nostril area,its presence is realized to the minimum possible extent. Further, thepatient may eat, talk, and move his head while the cannula remainsfirmly, yet comfortably, in place. The fat upper surface which restscomfortably against the patients anterior nares prevents cannularotation thereby maintaining its proper position with the gas directingtubular extensions located within the nostrils rather than slip ing outeven though the supply tubes are rolled or tume somewhat. The cannulaalso 0 ers the advantage of being simple in design, and in expensive tofabricate. The composition of the cannula is preferably of thethermoplastic composition such as polyvinyl chloride or polyvinylacetate which materials are understood to be quite pliable or flexible.Alternatively, the cannula may be fabricated from a rubber compositionor other flexible synthetic materials. The cannula obviates therequirement of straps or bands thereby also simplifying manufacturingtechniques and reducing costs. The unitary device may be produced by asimple molding operation with the oxygen supply tubes then attachedprior to or at the time of use.

We claim:

1. A nasal cannula comprising:

an elongated body adapted to have minimal contact with a patients upperlip, said body having a tunnel extending through the length thereofterminating in an oxygen supply opening at each end, the body having alength sufficient to span the width of an average patients nostrils andan upper essentially flat surface portion being relatively thin in crosssection for resting against a patient's anterior nares and a pair ofspaced hollow tubular extensions'integral with and projecting upwardlyfrom said flat surface which extensions terminate at a gas directingorifice and which hollow portion of said extensions communicate withsaid tunnel.

2. The cannula of claim 1 wherein the tubular extensions are curved.

3. The cannula of claim 2 wherein the tubular extensions join said flatsurface at an obtuse angle.

4. The cannula of claim 1 wherein the hollow portion of each of saidextensions communicates with said tunnel at a first orifice andterminates at its opposite end in a gas directing orifice said gasdirecting orifice being larger than said first orifice.

5. The cannula of claim 4 wherein said hollow portion of said extensionsis flared uniformly between said first and said gas directing orifice.

6. The cannula of claim 1 having a flexible oxygen supply tube extendingfrom each tunnel opening.

7. The cannula of claiml composed of a flexible material.

8. The cannula of claim 8 wherein the flexible material comprises athermoplastic resin.

9. The cannula of claim 8 wherein the resin composition is selected fromthe group consisting of polyvinyl chloride and polyvinyl acetate. 7

10. The cannula of claim 1 wherein the length of said body is betweenabout 1% and about 2 inches.

11. A nasal cannula for delivering oxygen containing gas comprising:

a. a generally flattened upper body portion having a flat upper surfacefor resting against a patient's anterior nares said upper surface havinga length sufficient to span the width of an average patients nostrils,said body portion being thin in cross section so as to have minimalcontact with a patients upper lip,

a hollow tunnel portion of substantially the same length as said upperbody portion and attached to the underside "of said upper body portionand tenninating in an oxygen supply opening at each end, and

c. a pair of spaced hollow tubular extensions projecting upwardly fromand integral with said flat surface, each end of said extensionscommunicating with said tunnel at a first orifice and terminating at itsopposite end in a gas directing orifice.

12. The cannula of claim 11 wherein the length of said upper bodyportion is between about 1% and about 2 inches.

13. The cannula of claim 11 having a flexible oxygen supply tubeextending from said tunnel ends.

(Hint In I A

1. A nasal cannula comprising: an elongated body adapted to have minimalcontact with a patient''s upper lip, said body having a tunnel extendingthrough the length thereof terminating in an oxygen supply opening ateach end, the body having a length sufficient to span the width of anaverage patient''s nostrils and an upper essentially flat surfaceportion being relatively thin in cross section for resting against apatient''s anterior nares and a pair of spaced hollow tubular extensionsintegral with and projecting upwardly from said flat surface whichextensions terminate at a gas directing orifice and which hollow portionof said extensions communicate with said tunnel.
 2. The cannula of claim1 wherein the tubular extensions are curved.
 3. The cannula of claim 2wherein the tubular extensions join said flat surface at an obtuseangle.
 4. The cannula of claim 1 wherein the hollow portion of each ofsaid extensions communicates with said tunnel at a first orifice andterminates at its opposite end in a gas directing orifice said gasdirecting orifice being larger than said first orifice.
 5. The cannulaof claim 4 wherein said hollow portion of said extensions is flareduniformly between said first and said gas directing orifice.
 6. Thecannula of claim 1 having a flexible oxygen supply tube extending fromeach tunnel opening.
 7. The cannula of claim 1 composed of a flexiblematerial.
 8. The cannula of claim 8 wherein the flexible materialcomprises a thermoplastic resin.
 9. The cannula of claim 8 wherein theresin composition is selected from the group consisting of polyvinylchloride and polyvinyl acetate.
 10. The cannula of claim 1 wherein thelength of said body is between about 1 1/2 and about 2 Inches.
 11. Anasal cannula for delivering oxygen containing gas comprising: a. agenerally flattened upper body portion having a flat upper surface forresting against a patient''s anterior nares said upper surface having alength sufficient to span the width of an average patient''s nostrils,said body portion being thin in cross section so as to have minimalcontact with a patient''s upper lip, b. a hollow tunnel portion ofsubstantially the same length as said upper body portion and attached tothe underside of said upper body portion and terminating in an oxygensupply opening at each end, and c. a pair of spaced hollow tubularextensions projecting upwardly from and integral with said flat surface,each end of said extensions communicating with said tunnel at a firstorifice and terminating at its opposite end in a gas directing orifice.12. The cannula of claim 11 wherein the length of said upper bodyportion is between about 1 1/2 and about 2 inches.
 13. The cannula ofclaim 11 having a flexible oxygen supply tube extending from said tunnelends.